Katharine Gun, who revealed a US “dirty tricks” campaign to justify invading Iraq, said on Thursday that the government wanted to increase repressive measures against whistleblowing.

“The government has increasing powers,” she said referring to the Investigatory Powers Act, known as “snooper’s charter”. Made law in 2016, the Act makes it easier for cops and spies to hack phones or emails.

Gun said, “The Official Secrets Act was already the most draconian secrecy law in the world and there’s this whole criminalisation of whistleblowing and journalism.

“Once governments gain that level of power they don’t relinquish it. They just build and build on it.”

Gun was speaking on a panel of whistleblowers to mark 15 years since her revelations were published in the Observer newspaper. It was organised by ExposeFacts and RootsAction.org.

The panel described the methods states use to facilitate and cover up their crimes—and the lengths they go to to punish those who expose them.

As a translator for British communications monitor GCHQ, Gun received a memo from US NSA spy agency describing plans to grease the wheels for war.

Drake explained that one role of the intelligence services is to produce “propaganda”.

“They have to generate a whole pack of lies to justify what they do,” he said. “What is most disturbing today is that to expose the wrongdoing and criminality of people in power is a criminal act in itself,” he added.

“You’re holding up a mirror—and they want to break the mirror and the person holding up the mirror.”

But Gun said it was still possible to challenge the government and state institutions—through leaks and through protest.

Her leak came amid the mass Stop the War movement that had swept Britain. She joined the massive demonstration in London on 15 February 2003—shortly after she leaked the documents but before they story was published.

“At the time of the march I didn’t know what had happened to the leak. I was in limbo. But going on that march, I thought the people have spoken out.

“It was so historic. It was an incredible feeling being squashed in that crowd of people. I thought Tony Blair must listen to us. Nobody can ignore this.”

She added, “Tony Blair was in fear. They really were very worried. If that level of protest had been maintained for several more days that may have had an effect.”